Apparatus for coating the edges of shoe soles



G. T. RALPHs 3,282,247

Nov. l, 1966 APPARATUS FOR COATING THE EDGES OF SHOE SOLES 6 Sheets-Sheetl l Filed July 2,4. 1962 ,NVENTOR N0 1, 1956 G. T. RALPHs 3,282,247

APPARATUS FOR COATING THE EDGES OF SHOE SOLES Filed July 24, 1962 6 Sheets-Sheet 2 lNvsN-roR GEORGE TREVOR RALPHS /B/ m/ HTTORNEYS Nov. 1, 1966 G. T. RALPHs 3,282,247

APPARATUS FOB COATING THE EDGES OF SHOE SOLES lNvsNToR GEORGE TREVR RALPHS 'E29 Mw/M .avv-omvsys Nov. l, 1966 G. T. RALPHs 3,282,247

APPARATUS Fon comme THE EnGEs oF sHoE soLEs Filed July 24, 1962 l e sheets-sheet 4 INVENTOR GEORGE TREVOR RALPHS B3 QW ATTORNEYS NOV. 1, 1966 G, T, RALPHS v 3,282,247

APPARATUS FOR COATING THE EDGES'OF SHOE SOLES Filed July 24, 1962 6 Sheets-Sheet 5 nvvENToR GEORGE TRU/0R RHLPHS 739 MQW n'rToRNtVS G. T. RALPHS Nov. l, 1966 3,282,247 APPARATUS FOR COATING THE EDGES OF SHOE SOLES Filed July 24'. 1962 6 Sheets-Sheet 6 GEORG/5 TREvoR RALPHS BH United States Patent() land Filed luly 24, 1962, Ser. No. 212,039 Claims priority, application Great Britain, July 27, 1961, 27 ,247 61 11 Claims. (Cl. 118-323) This invention is for improvements in means for operating on edge portions of workpieces and has for one ofits objects to provide a simple, convenient and effective apparatus for coating the edges of relatively thin Workpieces. The invention is particularly useful for `applying finishing coatings t-o the edges of shoe soles, the term shoe being used herein in a broad sense to include all forms of outer footwear wherever the context so permits.

In accordance with the invention there `is provided ,a means for applying a coating to the edge portions of relatively thin workpieces in the use of which a group of similar workpieces are superposed in a stack with their edges coincident as viewed in plan and coating material is sprayed on to the adjoining edges of the workpieces first along `one side thereof, and the workpieces are then turned to present another Jside thereof towards the spraying means and the coating material is sprayed on to the edges of the Workpieces along such other side. Thus a suitable plurality of workpieces have the coating operation performed on them simultaneously thereby effecting a saving in operating time and moreover the stacking of the workpieces provides that all except the `outermost workpieces in the stack are shielded by other workpieces from unwanted deposition of coating material on their faces adjacent to their edges. The end workpieces in the stack may be shielded by cover plates specially provided or they may be so positioned that their faces which are outermost are ones which are not specially required to be free of coating material.

In applying the invention to the edge finishing of shoe soles a group of precisely similar soles will be mounted in registry in a stack and held between suitable clamps and spraying of the coating material is first performed along one side of the soles from end to end and preferably slightly round the e'nds, the stack of soles is then turned through approximately 180 and spraying is continued along the other side of the soles from end to end thereof so as to complete the coating procedure. A convenient and expeditious way of applying the final prefinishing treatment to the sole edges is thus provided. It is important t-o avoid having the edge finish coating of stain or ink spreading from the edges on to that face of each sole which is to form the bottom face =of a shoe and this is provided by the masking effect of each sole upon the' face of another, the outer faces of the two end soles being either protected by masking plates of the same contour or being sole faces opposite to those which are to form the bottom faces of finished shoes. The group of 'soles treated may be a quantity appropriate to be used in making a batch of shoes eg. one dozen pairs and rights and lefts may be assembled in the same stack opposite ways up, or one or two dozen rights and a similar quantity of lefts may be treated separately in different stacks.

The invention provides apparatus for coating edge portions of workpieces comprising means for clamping a group of workpieces in ia stack upon one another with their edges coincident as seen in plan, means whereby the stack mounting means can `be turned about an axis at right angles to and passing through the workpieces at or near the centre thereof, spraying means, a mounting for the spraying means positioned alongside the stack mounting means, means for effecting relative traversing movement between the spraying means and the stack mounting means in the direction of the length Aof Workpieces mounted in the stack to effect spraying along one side of a stack of workpieces, and means for turning the stack of workpieces through approximately and thereafter reversing the relative movement between the spraying means and the stack mounting means.

In applying the apparatus to the edge coating of shoe soles the stack mounting means is arranged to receive a group of similar soles superimposed in registry with one another and to be c-apable of being turned through approximately 180 on an axis passing at right angles to the stack through the centre `or approximately the centre thereof, and the parts are so arranged that the relative movement between the stack holding means and spraying device is performed along a path which extends along the length of the soles in the stack and is partly arcuate at the ends thereof to effect spraying on to the edges of the soles at their ends as well as along -one side. When the stack has been turned and a reverse relative movement occurs between the stack holding means and the spraying device the coating of the edges is performed along the other side of the soles and completed at the ends thereof.

In practising the invention it is convenient to have the stack holding means carried on a stationary support so as to be capable of turning thereon about the said axis and to provide a carriage for the spraying device which is moved alongside the stack holding means in the required path rst in one direction and then in the opposite direction, the stack holding means being turned in between the opposite traversing movements of the sprayer carriage to present the sole edges at the other side of the stack to the spraying device.

A convenient apparatus embodying the foregoing and other provisions in accordance with the invention will now be `described Iby way of example, reference being made to the accompanying drawings illustrating the apparatus. In the drawings,

FIGURE 1 is a front perspective view showing the complete apparatus;

FIGURE 2 is an enlarged plan view of part of the apparatus as seen with upper coverings and certain other parts removed;

FIGURE 3 is a front elevation view of certain of the parts shown in FIG. I2;

FIGURE 4 is an end elevation view of certain of the parts shown in FIG. 2 and shows more particularly a work clamping arrangement;

FIGURE 5 is a detail View in end elevation and partly in cross section -of part of a traversing means;

FIGURE 6 is a partial plan view corresponding to part of FIG. 2 but on a slightly larger scale showing supporting means for a sprayer;

FIGURE 7 is a side elevation view as seen from the right of FIG. 6 of parts shown therein, and

FIGURE 8 is a pneumatic circuit diagram showing how the operating parts are inter-related.

Referring firstly to FIG. 1 the apparatus shown is adapted for spray coating the edges of shoe soles. It comprises a box-like lower casing 10 having a removable front cover 11 to permit access to parts such as compressed air supply means contained in the casing 10. At the lower part of the casing there is a treadle 12 for actuation by the operator when required during insertion and removal of the work. Above the casing 10 there is an upper casing 13 having a slanted forward portion 14 on the front of which there is an instrument and control panel 15. The latter is provided with pressure gauges 16 and control 9 knobs 17, 18 and 19 for controlling respectively a main valve, a start valve and a stop valve. Above the casing 13 there is an upper table 29 having its front portion curved rearwardly towards its sides from a straight central portion. Projecting forwardly from below the forward edge of the table 20 is an apron strip 21 having a straight central part and backwardly curved ends corresponding in shape to the forward edge of the table 2f).

Between the table 20 and the apron strip 21 there is a horizontal slot through which projects an arm 22 carrying near its end a bracket 23 from which upstands a post 24 on which there is mounted a spray gun 25 by means of a bracket 26 and clamping cleat 27. The spray gun is operated by compressed air supplied through pipes 28 and 29 one of which supplies air for ejection from the nozzle of the gun and the other of which supplies air for operating an on and off valve. At about the centre of the table 2) there upstands through it a spindle 39 carrying a bottom clamp strip 31 which is disposed opposite a similar top clamp 32 carried at the lower end of `a depending spindle 33 extending downwardly from a casing 34. The latter is carried on a back post 35 and contains a pneumatic cylinder to be referred to later, whereby the top clamp plate 32 may be moved up and down for insertion and clamping of a stack of soles S between the clamping strips 31 and 32.

When soles are in position between the clamping strips 31, 32, as shown, the spray gun 25 is directed towards the edges of the soles and it is adjustable on its supporting bracket 26 and post 24 so that it can be positioned at the same level as about the centre of the stack S and pointed directly towards the stack, or raised to a level above the stack and directed downwardly at a slant angle towards the edges of the soles in the stack. The spray gun is arranged to be traversed from side to side to effect relative traversing movement between the spray gun and the soles S from end to end of the soles along one side thereof and partly round their ends so as to spray ink or stain on to the sole edges along one side and partly at their ends. Thereupon the spindles 30 and 33 are turned to turn the stack of soles S through 180 and present their other side edges towards the spray gun and the latter is traversed back along the side of the stack and partly round its ends. The means for traversing the spray gun and turning the stack of soles will now be described more fully.

Referring more particularly to FIGS. 2 and 3 which show parts contained within the casing 13, 14, there can be seen side frame members 36 and a rear frame member 37 which support other frame members 38 and 39 carried on side pieces 40. The frame member 39 carries upstanding struts 41 by which there is supported the forward part of a table 42, the rear part of which is secured to angle strips 43 fixed to the two sides of the post 35 previously mentioned which in turn is secured by an angle strip 44 to the frame member 38. Also mounted on the frame member 39 on upstanding struts 45, and supported forwardly by a rod 83 (FIG. 4), is a track plate 46 having a straight central portion and inwardly curved ends of quadrant shape in plan. Mounted on the table 42 by bolts 48 at its ends is a slotted plate 49 being raised somewhat from the table 42 by means of spacers 47. The plate 49 is formed with a slot 50 having a straight central portion and inwardly curved ends. The end portions of the slot 50 like those of the track plate 46 are concentric with two spindles 51 upstanding from the table 42 and carrying chain sprockets 52. These it will be seen are positioned as seen in plan on opposite sides of and in lateral alignment with the spindle 30 carrying the bottom clamp strip 31. A chain 53 runs around the sprockets 52 and also around more rearwardly spaced sprockets 54 on spindles 55 upstanding from the table 42, the left hand spindle being adjustable on the table for adjustment of the tension in the chain 53.

The chain 53 is adapted to be driven through a partial circuit first one way and then in reverse and thereby to traverse the spray gun 25 in the required manner. The chain movement is effected by a rack quadrant 56 carried by a lever 57 pivoted at 53 to a mounting on the frame member 38. The lever 57 is shown in side view in FIG. 5 and has two spaced rearwardly extending arms 59 and 6@ attached by spacers 61 and 62. The arms 59 and 66 are coupled at 63 and 64 to the piston rods of two cylinders 65 and 66 pivoted at 67a to a bracket 67, FIGS. 2 and 4, bolted to frame member 38. The upper cylinder1 65 is a double acting pneumatic cylinder for operating the quadrant 56 while the lower cylinder 66 is a control or dashpot cylinder to control the rate of movement of the quadrant 56. Conveniently the rack quadrant 56 consists of a plate carrying a curved bar to which is secured a length of roller chain to present chain rollers in place of rack teeth. Such rollers engage a further sprocket 68 on the left hand spindle 55 below the table 42.

As shown more particularly in FIGS. 6 and 7, the arm 22 which carries the spray gun Ibracket 23 and post 24 extends outwardly from a carrier assembly consisting of upper and lower plates 69, 79 positioned above and below the slotted plate 49 and straddling the slot 59. The arm 22 is secured by fixing screws 71 to the upper plate 69 and a further short plate 72 secured by fixing screws 73 to the top Iof plate 69 extends over the chain 53 and connects the carrier 69, 79 thereto. The connection to the chain is by means of a short strip '74 xed to a link of the chain and carrying an upstanding pivot pin 75, FIG. 7, to which is pivoted a slide block 76 running in a sl-ot 77 in the plate 72. The carrier `69, 70, is guided by the slot 59 by mean-s of two rollers 78, rotating on spindles 79, extending between the plates 69 and 79, the rollers 78 being contained in the slot 59 and |being slightly smaller than the width of the slot. Between the carrier 69, 7@ and the outer end of arm 22 there is secured to the underside of the arm by screw-s 89 a block 81 carrying a rotatable track roller 82 to run on `the track plate 46. Thus it will be seen that as the chain 53 is moved through a -suicient part of its circuit it will drive the arm 22 to move the spray gun from one extreme position in which it points towards one end of the stack of soles S firstly along an arcuate path then along a straight path and then along a further arcuate path to the other extreme lof travel in which the gun points to .the other end of the stack of soles. During its stroke the spray gun is maintained directed towards the stack `of soles by the guiding action of the slot 59 and the rollers '78 running therein which maintain the arm 22 always orientated in the required direction.

Referring more particularly to the manner of mounting the stack of workpieces constituted by the soles S the post 35 has extending forwardly from its upper end an Outrigger bracket S3 which supports above its forward end a pneumatic cylinder S4 having a piston rod 85 extending downwardly and carrying at its lower end a ybearing block 86. In a bearing 37 in the Iblock 86 there is mounted -a stub `spindle which is the spindle 33 aforementioned carrying the upper clamp strip 32. The clamp strip can thus turn freely about the axis of the piston rod 85 whilst pressure is applied by the pneumatic cylinder 84 to clamp the soles S between the clamp strips 31 and 32. The lower clamp strip 31 is secured to an upstanding spindle 89 which turns in a bearing in the table 42 and also in a bearing in an upper bearing plate 90 supported =by posts 91 from the table 42. The lower end of spindle S9 carries a sprocket gear 92, FIG. 2, which is engaged -by a rack bar 93 formed by .a plain bar having a length of roller chain secured to one side of it to engage with the teeth of sporcket 92. The opposite side of the rack bar 93 is engaged yby a roller 94 which holds its roller chain in engagement with the sprocket 92. The rack bar 93 is secured to a piston rod 95 of a pneumatic cylinder 96 mounted in fixed position on the frame at a level below the table 42. The pneumatic cylinder 96 has a stroke such that it will move the rack bar 93 to turn the spindle 89 carrying the `bottom clamp strip 31 through at least 180, an adjustable stop member 97 being provided on a xed bracket 98, so that the stroke can be adjusted to exactly the right amount.

The apparatus described is operated entirely pneumatically from a common supply of compressed air and arrangements are made so that a succession of movements can be performed automatically in correct sequence. To -this end pneumatic trip valves indicated generally at 99, 100, are provided for engagement by operating projections 101, 102, on the ends of the rack quadrants 56 so that at one end of the travel of the quadrant trip valve 99 is operated and at the other end of its travel trip valve 100 is operated, both valves being released at intermediate positions of the quadrant. In addition pneumatically operated circuit control valves indicated at 103, 104, in the circuit diagram of FIG. 8 are provided to control the op-v eration of other parts in required manner.

The apparatus illustrated is equipped with mechanism by means of which a plurality of complete traverses of the spray gun can be caused to occur in each direction in alternating succession, and the stack of the soles turned through 180 between successive strokes of the spray gun in opposite directions. To this end there is mounted on -a bracket 105 upstanding from the frame member 38 a horizontal plate 106 mounted for lateral adjustment on a pair of screws 107. The plate supports rotatably an upstanding spindle to which there is secured by a -screw 108 a disc 109 formed with three equally spaced flats 110 at its edge and carrying a circular row of upstanding pins 111. The edge of the disc 109 co-operates with a plunger of a pneumatic control valve 112 mounted on the supporting plate 106. Also secured to the spindle carrying 4the disc 109, just below the disc, there is Ia triangle shaped cam member 113 which co-operates with a plunger of a further pneumatic contr-ol valve 114 mounted on the supporting plate 106.

The disc 109 and cam member 113 are arranged to be racked round in a clockwise direction, as seen in FIG. 2, by a pawl 115 pivotcd at 116 to a supporting plate 117 secured to the left hand end of the quadrant 56. The pawl 115 has a pin and slot guiding means indicated at 118 and is urged to rock clockwise, as seen in FIG. 2, .about its pivot 116 by means of a spring 119. Thus it will be understood that when the quadrant 56 in rocking clockwise, i.e. to the left in FIG. 2, reaches the end part of its travel, the pawl 115 will engage with one of the pins 111 and step the disc 109 and cam member 113 round Iby one space. The arrangement shown operates so that when the parts are in position with the control valve 112 co-operating with a flat 110 on disc 109 and the control valve 114 just cleared from one of the projecting corners of cam member 113, three swings of the quadrant 56 to the left are necessary to turn the disc 109 and cam member 103 suiciently to bring t-he parts again into a similar position.

Reference will now be made to the pneumatic ycircuit diagram of FIG. 8 in which there is indicated a main pipe 120 leading from a sourceof compressed air through a main stop cock 121 controlled by the operating knob 17 on the panel. The main pipe 120 is connected to branch pipes 122 and 123 in which are connected pressure gauges 124 and 125, air filters 126 and 127 and a lubricator 128. The branch pipe 122 leads to the flexible pipe 28 supplying air to the nozzle of the spray gun 25 and connects the air supply permanently thereto. The branch pipe 123 leads to connections 129 and 130 to a spring returned control valve 131 operated by the treadle 12,

for admitting air through pipes 132 and 133 alternatively Ito the opposite ends of sole clamping cylinder 84. The arrangement of the valve 131 is such that when the treadle 12 is released the top end of the cylinder 84 is connected through the control valve 131 to the supply so as to urge the top clamping strip downwardly. Wherever the clamping strip is to be released thettreadle 12 is depressed so as to exhaust the top end of the cylinder 84 to atmosphere and connect its bottom end to the air supply. From the pipe 123 there is a connection 134 leading to the manual push-pull stop valve 135 operated by a knob 19, from which valve further pipes 136 and 137 lead respectively to centre inlet ports of pneumatically operated valves 103 and 104. From pipe 137 there is a pipe connection 138 joining with a connection 139 running between the normally closed control valves 99 and 100, other connections to which consist of a pipe 140 running from valve 99 to a push-button starting valve 141 operated by button 18 on the control panel 15, and a pipe 142 connecting valve 100 to one end of the pneumatically operated valve 104. The opposite end of valve 104 and one end of valve 103 are connected by pipes 143, 144 and 145 to the opposite side of the starting valve 141 to which therealso extends a pipe 146 running from the control valve 112 associated with disc 109, a one way valve 147 being interposed in.` this pipe connection so that air can flow in the direction from the valve 112 to the pipe 145. The other side of the valve 112 is connected by a pipe 148 to the pipe connection 140. The valve 114 associated with the triangle cam 113 is connected by pipes 149 and 150 between the pipe 138 and the operating connection of valve 103 opposite to that connected to pipe 144. A pipe 156 connects an outlet port of valve 103 to the exible pipe 29 and other pipes 157 and 158 connect the opposite ends of the travepsing cylinder 65 to different ports of the valve 104. The work rotating cylinder 96 has its opposite ends connected by further pipes 159 and 160 to other ports of the valve 104.

As shown in FIG. 8 the control cylinder 66 serves as a dashpot to retard the swinging motion of lever 57 and consequently the rate of traverse of the spray gun, and is connected at its opposite ends through restrictors 151 and 152 to a reservoir 153 by means of pipes 154 and 155. The cylinder 66, pipes 154 and 155 and the reservoir 153 contain liquid, for example oil, which due to its relative incompressibility and the resistance to its passage through restrictors `151 and 152 has a retarding action on the piston in cylinder 66 which retarding action is adjustable in known manner by adjustment of the restrictors 151 and 152 acting on the liquid ilow in opposite directions.

The operation of the apparatus just described is as follows. Commencing with the apparatus in its rest position in which the quadrant 56 and the spray gun are in their extreme left hand settings and with the stop valves 121 and 135 open, a stack of soles is clamped between the clamp plates 31 and 32 and the start button 18 is depressed thus opening the normally closed valve 141. At this juncture air passes from main pipe 120 through pipe 122 and flexible pipe 28 to the sprayer nozzle, but the sprayer is inactive since its control valve which is spring closed has not yet been actuated by air pressure. However an air circuit is established from main pipe 120 through filter 127, lubricator 128 and pipes 134, 137, 138 and 139 to the valve 99 which is held open by the quadrant 56. From valve 99 the circuit continues through pipe 140, starting valve 141 and pipes 145, 143 and 144 to the pneumatically operated valves 104 and 103. These valves are then operated so that on the one hand through valve 103 the sprayer 25 is actuated by air Ipressure passing through pipes 136 and 156 to the flexible pipe 29 so as to open to control valve in the sprayer 25. Operation of valve 104 causes its plunger to move so as to connect the pipes 157 and 160 to the inlet port and inlet pipe 137, and exhaust pipes 158 and 159 to atmosphere. Air is then admitted into one end of work rotating cylinder 96 and the right hand end of traversing cylinder 65. The work rotating cylinder 96 responds immediately without retardation so that the stack of soles S is turned through without delay. On the other hand the action of traversing cylinder 65 is retarded by the control cylinders 66 and the quadrant 56 commencesV to turn icounterclockwise slowly. The spray gun is thus traversed slowly from right to left pointing to the stack of soles S and guided by engagement of the rollers 78 in the slot 50 of the plate 49 so as to be kept directed at the soles. As the quadrant 56 moves away from its left hand setting it releases the plunger of valve 99 which thereby closes. When the spray gun reaches the right hand limit of its travel the quadrant 56 engages the plunger of valve 100 and opens the valve thus connecting supply pipe 137 through pipes 13S, 139 and 142 to the opposite control port of valve 104 seen at the bottom in FIG. 8. This causes the control plunger of valve 104 to be shifted back =to its original position disconnecting the pipe 137 from the pipes 157 and 160 and connecting it instead to the pipes 158 and 159, at the same time exhausting pipes 157 and 160 to atmosphere. Thereupon the cylinders 96 and 65 are energised, the one for reverse turning of the soles S and the other for performance of the reverse transverse movement of the spray gun. The work turning `cylinder 96 responds immediately causing the spindle 89 and clamp strips 31 and 32 to be turned back through 180 to cause the other side edges of the soles to be presented to the spray gun 25. A traverse of the spray gun 25 from left to right then takes place with the initial movement of quadrant 56 causing valve 100 to become closed.

In the initial rest position of the parts the disc cam 109 is positioned with one of its flats 110 in co-operation with the plunger valve 112 and it remains in this position until towards the end of the left hand swing of the quadrant 56 when the pawl 115 on quadrant 56 engages one of the pins 111 to turn the disc cam 109 out of the position just mentioned. Thereupon the valve 112 is opened, the opening movement Voccurring just before the quadrant 56 reaches the end of its clockwise travel. Thereafter the valve 112 will remain yopen whilst its plunger is engaged by the hump of the disc 109 until the disc moves round to bring the next succeeding at 110 into cooperation with the valve plunger. The opening of valve 112 establishes an air pressure circuit from the valve 99 through pipes 148, 146 and 145 and one way valve 147 to the pipe 143 connected to the opposite control port of valve 104 to that-last energised. Thus when valve 99 is opened by the quadrant 56 the pipes 157 and 160 are caused by valve 104 again to be connected to the inlet pipe 137 and the pipes 158 and 159-are discharged to the atmosphere. This causes the position of the soles S and the direction of traverse of the spray gun to be again reversed and at the conclusion of the next traversing stroke the pawl 115 engages one of the pins 111 to rack the disc 109 by one further step the valve 112. being however still held open.

Further reversals of the soles S and the direction of traverse of the spray gun occur until the quadrant 56 moves back towards the control valve 99 and on this occasion the pawl 115 racks the disc 109 to bring the next flat 110 into co-operation with the plunger of valve 112 whereupon the valve closes. Immediately before this occurs the triangle cam 113 has also been moved by the turning of disc 109 to cause one of its humps to move past and operate the plunger of valve 11d. This causes connection of the air pressure pipe 137 through pipes 138, 149 and 150 to the control port `of valve 103 seen on the left in FIG. 8. The ycontrol plunger of valve 103 is thereby moved to its opposite setting so as t disconnect pipe 156 from the inlet pipe 136 and exhaust it to atmosphere causing the control valve in the spray gun 25 to close and thereby cause the spray gun to cease operating. When the quadrant 56 trips the valve 99 on this occasion the apparatus will cease operating since the valve 112 being closed will break the circuit between the pipe 148 and the pipes 146 and 145, reverse actuation of valves 104 and 103 being Iconsequently prevented. The parts of the apparatus have then been returned to and will remain in rest position.

A spraying operation having been completed on a stack of soles S the operator then depressed the treadle 12 to operate the cylinder 84 for release of the soles by raising the upper clamp strip 32. The operator can then remove the stack of soles and replace it with a stack of fresh soles, thereupon releasing the treadle 12 to clamp the soles and repeating the spraying sequence by operation of the start button 18.

It will be evident that the apparatus herein described is particularly adapted for the performance of an improved method yof applying a coating to the edge portions of relatively thin workpieces. In accordance with such method a group of similar workpieces such as the shoe soles S are superposed in a stack with their edges coincident as viewed in plan. Whilst in the stack coating material is sprayed on to the adjoining edges of the workpieces firstly along one side thereof by causing traversing movement of the spray gun 25 to produce relative movement between it and the stack of soles S longitudinally of the latter.` The soles S are then turned about the common axis of the spindles 30 and 33 to present another side of them towards the spray gun 25 and return movement of the spray gun takes place producing reiative movement between it and the sole S Icausing the coating material to be sprayed yon to the edges of the soles along such other side. The traversing movements cause the coating material to be sprayed first from end to end of the stack on one side and slightly round the ends of the soles and afterwards from end to end of the other side of the soles and partly round the ends. Preferably in practising the method the spraying of the coating material first along fone side of the soles S and then along the other side of them is carried out a plurality of times before the stack of soles is released from the clamps*` as is provided by the automatic control arrangement in the apparatus described.

When applying an redge nish coating of stain or ink to shoe soles it is important to avoid spreading of the coating from the edges on to that face of each sole which is to form the bottom face of a shoe. The masking effect of each sole upon the face of another can be utilized for this purpose, the outer faces of one or both of the two end soles being either protected by a masking plate or plates of the same contour interposed between the stack and the appropriate clamping strip or strips. Alternatively the end soles may both present outwards sole faces opposite to those which are to form the bottom faces of the inished shoe. The group of soles treated may be a quantity appropriate to be used in making a batch of shoes and may consist for example of a dozen pairs of rights and lefts assembled in the same stack opposite ways up. Alternatively rights and lefts may be treated separately in different stacks with a masking plate at one end t0 protect the bottom finished sur-face of the end soles. To assist in avoiding seepage of the coating material between the soles in a stack the spray gun 25 may be elevated on the rod 24 and directed towards the soles with a downward slant.

In compiling a group of soles into a stack for clamping between the clamp strips 31 and 32, use may be made of the method and apparatus described in co-pending U.S. application Serial No. 198,989 filed May 3l, 1962. If desired the method and apparatus herein described may moreover be employed for coating the edges of shoe soles when practicing the pre-finishing method protected in said co-pending patent application.

In practice the apparatus illustrated in the drawings will normally be mounted within a `spraying booth to protect the apparatus from stray air currents which might interfere with its effectiveness, and also to prevent the sprayed coating material from reaching neighbouring parts or apparatus.

What I claim is:

l. Apparatus for use in edge coating of shoe soles, comprising means for clamping a group of similar shoe soles superimposed in a stack one upon another with their edges coincident as seen in plan, means whereby the stack mounting means -can be turned through approximately 180 about an axis at right angles to and passing through the shoe soles centrally thereof, spraying means, a mounting for the spraying means to position the latter alongside the stack mounting means and directed towards the stack mounting means, means for electing to and fr-o relative traversing movement between the spraying means and the stack mounting means lengthwise .of shoe soles mounted in the stack to elfect spraying along the sides of such shoe soles, and means for turning the stack of shoe soles through approximately 180 to expose opposite sides of the stack in turn to the spraying means, wherein the parts are so arranged that the relative movement between the stack mounting means and the spraying means is performed along a path which extends along the length of the soles in the stack `and is partly arcuate at the ends thereof to effect spraying on to the edges of the soles at their ends as well as along one side.

2. Apparatus according to claim 1 having the stack mounting means carried on a stationary support so as to be capable of turning thereon about the said axis at right angles to .the workpieces, and having a carriage for the spraying means which is moved alongside the stack mounting means in the required path iirst in one direction and then in the opposite direction, and having means for turning the stack mounting means between opposite .traversing movements of the sprayer carriage to cause the edges of the workpieces on the opposite sides of the stack to be presented Ito the spraying means.

3. Apparatus according to claim 2 comprising a guide plate extending along the path of the carriage and formed with a guide slot, and spaced rollers mounted on the carriage to engage in the guide slot, the latter being 'so shaped as to control both the path of the spraying means and required changes in the direction of the spraying means towards the ends of its traversing movement.

4. Apparatus according to claim 2 comprising an endless chain, sprockets supporting said chain so as to present a stretch thereof extending in the direction of movement of the carriage, means coupling the carriage to the stretch of chain so as to be traversed thereby, a pivoted rack quadrant coupled to the chain and means for rocking the quadrant alternately in opposite directions to the appropriate extent to traverse the carri-age through a required stroke.

5. Apparatus according to claim 4 wherein the quadrant is operated by a pneumatic cylinder.

6. Apparatus according to claim 1 comprising clamping members between which a stack of workpieces can be clamped, aligned rotatable spindles on which the clamping members are mounted, mounting means for one of said spindles slidably supported to provide for movement of such spindle towards the other spindle to effect the clamping action and a pneumatic cylinder coupled to said mounting means for effecting a clamping movement.

7. Apparatus according to claim 6 comprising a pneumatically operated slidable rack and a rack wheel engaged by said r-ack and coupled to one of said aligned rotatable spindles to elTect turning of the spindle for swinging the workpieces through 8. Apparatus according to claim 1 comprising a control arrangement whereby after clamping a group of workpieces in a stack relative traversing movements between the stack mounting means and the spraying means are caused to occur in opposite directions along the length of the workpieces in succession automatically with intermediate turning of the stack workpieces through 180 to present different edges of the workpieces to the spraying means.

9. Apparatus according to claim 8 wherein the control arrangement comprises means for arresting operation of the apparatus and the action of the spraying means at the conclusion of la complete cycle of movement.

10. Apparatus according to claim 9 comprising step -by step operated means actuated 4at the conclusion of each complete cycle of movements and arranged to cause stoppage of the apparatus after a plurality of complete cycles of movement have been performed.

11. Apparatus according to claim 1 wherein the clamping means for the workpieces, the turning means for the stack mounting means, and the means Vfor electing rel-ative traversing movement between the spraying means and the stack mounting means are all operated pneumatically from a common supply of compressed air from which the air blast .for the spraying means is also supplied.

References Cited by the Examiner UNITED STATES PATENTS 1,313,670 8/1919 Burdick 118-321 1,690,344 11/1928 Pohrt 118-321 1,806,583 5/1931 Boorman 117-44 1,953,376 4/1934 Uden 118-323 2,000,226 5/1935 Fry 117-44 2,345,834 4/ 1944 Schweitzer 118-321 2,3 68,829 2/ 1945 Harrington 118-321 X 2,574,675 11/1951 Walker 118-314 X 2,832,308 4/1958 Schmidt 118-30'1 X FOREIGN PATENTS 954,005 `6/ 1949 France.

DANIEL BLUM, Primary Examiner.

JOSEPH B. SPENCER, Examiner. 

1. APPARATUS FOR USE IN EDGE COATING OF SHOE SOLES, COMPRISING MEANS FOR CLAMPING A GROUP OF SIMILAR SHOE SOLES SUPERIMPOSED IN A STACK ONE UPON ANOTHER WITH THEIR EDGES COINCIDENT AS SEEN IN PLAN, MEANS WHEREBY THE STACK MOUNTING MEANS CAN BE TUNED THOUGH APPROXIMATELY 180* ABOUT AN AXIS AT RIGHT ANGLES TO AND PASSING THROUGH THE SHOE SOLES CENTRALL THEREOF, SPRAYING MEANS, A MOUNTING FOR THE SPRAYING MEANS TO POSITION THE LATTER ALONGSIDE THE STACK MOUNTING MEANS AND DIRECTED TOWARDS THE STACK MOUNTING MEANS, MEANS FOR EFFECTING TO AND FRO RELATIVE TRAVERSING MOVEMENT BETWEEN THE SPRAYING MEANS AND THE STACK MOUNTING MEANS LENGTHWISE TO SHOE SOLES MOUNTED IN THE STACK TO EFFECT SPRAYING ALONG THE SIDES OF SUCH SHOE SOLES, AND MEANS FOR TURNING THE STACK OF SHOE 